The headroom above and below an amplifier's DC output voltage determines the magnitude of the signal swing that the amplifier can produce before the amplifier output distorts an input signal. For a capacitive sensor which mates to a preamplifier, prior art circuits use a high impedance (high-z) diode network at the sensor interface to conserve the charge stored on the sensor. This high-z network also sets the DC voltage level at the amplifier input, which is commonly set to circuit ground. In turn, there are internal voltages within the preamplifier which will be referenced to the input DC level, possibly also including the output voltage based on the chosen architecture. As the positive power supply increases, these nodes will not follow with it, which can generate an asymmetry in the available signal headroom within the amplifier, which can cause distortions in the preamplifier output. Consequently, improvements to amplified capacitive sensor systems that reduce distortion in amplifier output would be beneficial.